The image shows a model of a lithium atom.

How many neutrons are in this lithium atom?

• 3

• 4

• 7

• 10

Tags

NGSS.MS-PS1-1

How many electrons does one neutrally charged atom of argon have?

• 18

• 22

• 40

• 58

Tags

NGSS.MS-PS1-1

How many neutrons are there in ²²⁶Ra?

• 88

• 138

• 226

• 314

Which of the following represents a pair of isotopes?

• Ca⁺², Be⁺²

• ¹²C, ¹⁴C

• Fe⁺², Fe⁺³

• ⁷N, ⁸O

Read the passage and use the diagram to answer the next question.

Silicon is the second most abundant element in Earth’s crust. It is used in the electronics industry to manufacture transistors, and in the construction industry to produce concrete and Portland cement.

What could be the estimated atomic mass of Silicon?

• 26.2 amu

• 28.1 amu

• 29.8 amu

• 30.1 amu

1. What is the lowest possible energy level that an electron can occupy?

• Excited state

• Fundamental state

• Ground state

• Outermost state

1. If the hydrogen atom emits red, blue-green, blue, and violet light, how many energy levels does it have in the visible region of the spectrum?

• 3

• 4

• 5

• 6

Tags

NGSS.HS-PS4-1

NGSS.HS-PS4-3

1. How many electrons are located in the outermost orbit in the Bohr model of a boron atom?

• 1

• 2

• 3

• 4

Tags

NGSS.MS-PS1-1

1. The figure shows different possible transitions of electrons as they move from higher energy states to lower energy states.

3. Which transition will produce the spectrum line with the lowest wavelength in this element’s atomic spectrum?

• A

• B

• C

• D

Tags

NGSS.HS-PS4-1

NGSS.HS-PS4-3

Read the passage and use the diagram to answer the next question.

Oxygen is perhaps the most important atom on Earth. It is responsible for life as we know it, and it is the most abundant atom in our planet. There are more oxygen atoms on Earth than all the other elements’ atoms combined. It was discovered as an atom by Antoine Lavoisier in 1777.

The image shows the Bohr atom model for Oxygen. 

1. Which of the following electronic transitions in the oxygen atom will result in light emission?

• n_i = 1 ⟶ n_f = 2

• n_i = 1 ⟶ n_f = 3

• n_i = 3 ⟶ n_f = 2

• n_i = 2 ⟶ n_f = 3

Tags

NGSS.MS-PS1-1